There is known a structure for attaching a cover for waterproof or sound insulation to a wire-led side of a connector wires of which are led from terminals within a connector housing (Japanese Patent Application Laid-open No. H07-263068). With this structure, a plurality of male connectors are inserted into the cover, and the wires led from the wire-led side are accommodated in a wire accommodating member and led out from a leading outlet. This cover is made of soft synthetic rubber and attached to the connector housing via a seal member. The cover can prevent entry of water and transmission of sound from a wire-led side of a male connector.